LASER GLASS HOST COMPOSITIONS COMPRISING TeO{11 , Pbo AND ZnO

ABSTRACT

Laser glass host compositions for effective lasing amounts of Nd2O3 are disclosed, the host compositions comprising TeO2, PbO and ZnO in certain molar amounts. Methods of making highly efficient laser articles, including laser rods, also are disclosed. The new use of the above-described TeO2/PbO/ZnO glass compositions for forming laser articles are disclosed, the new use including forming laser articles from the glasses; pumping the laser articles to provide an energy inversion; and lasing the pumped articles.

United States Patent 1191 Cooley I 1451 Nov. 19, 1974 LASER GLASS HOST COMPOSITIONS COMPRISING TeO,, PbO AND ZnO 51 111111015 3/00, C030 3/12, C03c 3/30 581- Field of Search 1 06/47 Q, 47 R; 331/945 E; 252/3014 R, 301.4 F, 301.6 R

[56] References Cited UNITED STATES PATENTS 3,423,326 H1969 Redman 252/301.6 R

- FOREIGN PATENTS OR APPLICATIONS 736,073 8/1955 I Great Britain 106/47 Q 741,986 12/1955 Great Britain.. 106/47 Q 1,496,561 9/1972 Germany 106/47 Q OTHER PUBLICATIONS Stanworth, Tellurite Glasses, J. Soc. Glass Tech., Vol. 36, (1952), pp. 217-241, TP 845 5678.

Primary Examiner-Winston A. Douglas Assistant Examiner-Mark Bell Attorney, Agent, or Firm-Richard D. Heberling; E. J.

Holler [5 7 ABSTRACT Laser glass host compositions for effective lasing amounts of Nd O are disclosed, the host compositions comprising TeO PhD and 'ZnO in certain molar amounts. Methods of making highly efficient laser articles, including laser rods, also are disclosed. The new use of the above-described TeO /PbO/ZnO glass compositions for forming laser articles are disclosed, the new use including forming laser articles from the glasses; pumping the laser articles to provide an energy inversion; and lasing the pumped articles.

8 Claims, -1 Drawing Figure PATENTEL HEY I 9l974 INVENTION The present invention relates to glass host compositions for efficient laser articles, the host compositions comprising TeO PhD and ZnO in certain molar amounts and containing effective lasing amounts of Nd O The present invention also relates to methods of making laser articles with increased efficiency, the methods including melting laser glass batch-forming materials to provide a molten TeO /PbO/ZnO glass laser articles. Also it is desirable to provide novel methods for making same and to provide the new use for glass compositions comprising TeO PbO and ZnO in which the new use includes the steps of:

1.. forming a glass laser article from the glass composition that is a host for an effective lasing amount of zoai 2. pumping the laser article; and thereafter 3. lasing the pumped article.

It is an object of the present invention to provide a laser glass composition containing TeO PhD and ZnO in which the molar proportions thereof are defined in a general range by the area within the heavy lines connecting the points ABCDEF of the ternary diagram of the FIGURE of the drawings, the glass composition being a host for an effective lasing amount of Nd O It is an object of the present invention to provide a method for making a glass article, such as a laser rod, in which the method comprises the steps of:

l. melting laser glass batch-forming materials to provide a molten glass comprising TeO PbO and ZnO, in which the molar proportions thereof are defined in a general range by the area within the heavy lines connecting points ABCDEF of the ternary diagram of the FIGURE, the molten glass being a host for an effective lasing amount of Nd O 2. forming a glass laser blank from the molten glass; and

3. fabricating the laser article from the blank to provide a very efficient laser article.

It is an object of the present invention to provide the new use for a glass composition as a glass laser article in which the glass contains certain molar proportions of TeO PhD and ZnO that are defined by the area within the heavy lines connecting points ABCDEF of the ter- It is an object of the present invention to provide highly efficient glass laser articles, such as rods and discs, made from a glass composition comprising certain molar amounts of TeO PbO and ZnO, the composition being a host for an effective lasingamount of Nd O These and other objects will become apparent from the specification that follows, the appended claims, and the drawings, in which the FIGURE is a ternary diagram of the glass host composition of the present invention, in which the molar proportions of TeO PbO and ZnO are set forth in a general range and in a preferred range by the heavy lines connecting the points ABC- DEF and the points GHIJ, respectively, of the ternary diagram.

The present invention provides outstanding laser glass host compositions for effective lasing amounts of Nd O the host compositions comprising TeO PhD and ZnO in certain molar proportions thereof that are defined in a general range by the area within the heavy which the molar proportions thereof are defined in a general range by the area within the heavy lines connecting the points ABCDEF of the ternary diagram, the molten glass capable of acting as a host for an effective lasing amount of Nd O 2. forming a glass laser blank from the molten glass; and

3. fabricating the outstanding laser articles from the glass laser blank.

The present invention also provides the, new use for a glass composition as a glass laser article in which the glass comprises TeO PbO and ZnO in certain molar proportions that are defined in a general range within the area formed by the lines connecting the points ABCDEF in the ternary diagram, and in which the glass composition is a host for an effective lasing amount of Nd O the new use comprising the steps of:

l. forming a glass laser article from the glass composition comprising TeO PbO and ZnO;

2. pumping the laser article to provide an energy-inversion; and

3. passing monochromatic light through the article to provide a stimulated emission at a wavelength of about 1.06 microns.

A zinc tellurite glass consisting essentially of a major molar proportion of TeO and between about 20-40 molar percent of ZnO is described and claimed in the Redman US. Pat. No. 3,423,326. These zinc tellurite glasses were reported as having some fluorescent activity when doped with Nd203.

As previously indicated, the outstanding laser glass host compositions of the present invention exhibit much higher fluorescent activity than the zinc tellurite glasses of the Redman patent, the increased fluorescent activity indicating a greater lasing efficiency for lasing articles made from the host compositions of the present invention. As previously described, only certain molar proportions of TeO PhD and ZnO can be used to provide the highly efflcient lasing articles, such as rods and discs. The increase in fluorescent activity of the glasses of the present invention, when compared to the worklaser articles of the present invention, unexpectedly is at least about 50 percent over that of a zinc tellurite glass containing 65 mole percent TeO and 35 mole p ent Q-H The increase in fluorescent activity surprisingly is at least about 50 percent greater than that of a lithiacalcia-alumino silicate laser glass as set forth in U.S. Pat. No. 3,471,409, to Lee and Rapp, the laser composition containing the following ingredients in approximate mole percentages:

The highest fluorescent activity value for a zinc tellurite glass containing 65 mole percent TeO and 35 mole percent ZnO is about 2.09 when compared to the fluorescent intensity value of the above-described lithiag examples Ofthe Redman Patent, 15 g a y atleast calcia-alumino silicate glass laser, which is the referabout 0 p n n preferably at le about 60 r 70 ence glass, arbitrarily designated or held to be 1.0. percent. Often, the increase is at least about 50 percent The following examples are intended to illustrate the for the glass laser articles ofthe present invention when present invention and not to limit the same in any way. compared to the working examples of U.S. Pat. No. 3,423,326. There is no mention of any glass system 0 EXAMPLE 1 I other than that of a host composition consisting of tel- PART A lurium oxide and zinc oxide in the Redman patent. There is no suggestion in the Redman patent that highly A gram nielt prepare? by mlxmg reagent efficient laser articles can be made from a host compograde raw materials followmg molaf Percent and sition containing only certain molar proportions of 15 also for convemence we'ght percent wnh of 2, bO and Z nO. water flwh WWW Ingredients Mole Percent Weight Percent Host Glass Laser Article Host Glass Laser Article Te0 03.0 63.0 73.5 ZnO 32.0 31.6 18.7 18.5 PbO 5.0 4.7 7.7 7.5 ud o 0.7 1.7

In g the laser glass host Compositions of the The slurry was mixed for 10 minutes and poured into present invention ta n about -8 mole p r t a gold crucible. The crucible was placed in an air circuz. about mole percent and about 5 lating oven with the temperature maintained at 110C. mole Percent overnight to remove the water. The crucible was then Preferably the laser glass host Compositions of the 30 placed in an electric resistance furnace with the tem- Pteseht lhvehtioh comprise about mole Percent perature at 750C. for 3 hours, or until homogenous, 2, about mole Percent Pbo, and about 1045 after which the molten glass immediately poured into mole percent 2110- The above-described general a preheated (260C.) graphite mold forming a disc havranges and Preferred ranges of T602, Pbo and Zho in ing an 11/16 inch diameter and A inch thickness. The the host compositions are doped with an effective las- 35 graphite mold was placed i an annealing oven i ihg amount of 2 3a the general range of z a being tained at 340C. After 1 hour, at 340C., the tempera- -about mote Percent, the Preferred range of ture of the annealing oven was lowered at a rate of 2 s being about 03-10 "1016 Percent, and the P 38C. per hour to 250C. after which the annealing mum range of z a being about 04-09 mole P oven was turned off and the mold cooled to room tement- W 7 Mk 40 perature.

Good results have been obtained with glass host com- The solid, annealed glass disc was removed from the positions in which the glass comprises about 65 mole mold, wet ground and polished with close tolerance to percent TeO about 10 mole percent PbO, and about a thickness of 0.195 inches and a diameter of 0.687 25 mole percent ZnO; or about 80 mole percent TeO inches. The refractive index of the finished polished about 10 mole percent PbO and about 10 mole percent glass disc was measured to be 2.08.

ZnO; or about 75 mole percent TeO about 5 mole PART B percent PhD, and about 20 mole percent ZnO.

ln accordance with the present invention, as previ- The Polished glass disc from Part A w tested for ously indicated, the increase in fluorescent activity for Ofescence n ensity and decay time in a high power pulsed test system. The disc was placed in a holder and exposed to a beam oflight from an EG & G model FX 12-25 xenon flash lamp. The flash lamp had a flash duration of about 20 microseconds. The disc was not observed to solarize after repeated excitation by the flash lamp. The fluorescence intensity and decay time of the excited sample was measured by photographing the oscilloscope display of the 1060 nanometer fluorescent intensity versus time on a Tektronix Model 556, Dual Trace oscilloscope connected to an RCA S-l photomultiplier, having a narrow band pass filter.

The fluorescence intensity measurement was normalized against ED-2, a glass laser composition of Owenslllinois, lnc., comprising, in mole percent, 60.0% SiO 2.5% A1 0 27.5% M 0, 10% CaO, 0.16% CeO and 0.5% M 0 disclosed in U.S. Pat. No. 3,471,409, as Example 1. The fluorescence intensity was found to be 3.09 when normalized against the glass laser composi- 6 tion; 3.09 of the glas slaser composi- B of Example The normalized fluorescence intensity tion. as 3.8 and the corrected fluorescence intensity was The fluorescence intensity was corrected for the re- The fluorescence decay time was 135 o cfractive indices of the glass disc and the reference glass ondslaser composition by 5 EXAMPLE 4 FI (corrected) F! (normalized) [(l.56) /(n glass PART A disc) A l5 gram melt was prepared and polished glass discs prepared therefrom as described in Part A of Ex l The corrected fluorescence intensity was 1.69. The flul0 1, except th molar or i h percentages f hi g orescence decay time was 154 microseconds. materials were as f n Ingredients Mole Percent Weight Percent Host Glass Laser Article Host Glass Laser Article Teo 75.0 74.5 77.7 76.4 ZnO 15.0 14.8 7.9 7.7 PbO 10.0 9.9 14.4 14.2 M 0 0.7 1 6 EXAMPLE 2 The refractive index of the finished polished glass disc was measured to be 2.16. PART A A gram melt was prepared and polished glass discs PART B prepared therefrom as described in Part A of Example The polished glass disc from Part A was tested for flul, except the molar or weight percentages of the raw orescence intensity and decay time as described in Part materials \yqrq f tl a N of Example 1. The normalized fluorescence intensity Ingredients Mole Percent Weight Percent Host Glass Laser Article Host Glass Laser Article TcO, 65.0 70.8 69.8 ZnO 25.0 24.8 l3.9 l3.6 PbO 10.0 9.9 l.5 l4.9 Nap 0.7 1.6

The refractive index of the finished polished glass disc was 3.3 and the corrected fluorescence intensity was was measured t b 2,12, 1.74. The fluorescence decay time was I microseconds.

PART B Other specific glass laser compositions set forth The polished glass disc from Part A was tested for fluherein as being suitable for use in the present invention orescence intensity and decay time as described in Part 40 0.311 be substituted specific glass laser eemposi B of Example I. The normalized fluorescence intensity tlOnS d n the worklng examples to prov1de substanwas 3.1 and the corrected fluorescence intensity was a y equivalent reSultS- 9 instance, any of the com- 1.68. The fluorescence decay time was 145 microsecposltlof'ls Set forth wherem f area formed y the onds. heavy lmes connectmg the pomts ABCDEF, of the ternary diagram, can be used in place of thespecific laser EXAMPLE 3 compositions used in the working examples (such as PART A v the host glass of Example 1 that comprises 63 mole percent TeO 5 mole percent PbO and 32 mole percent ZnO) to provide an increased efficiency of at least about percent over that of the zinc tellurite glasses of the Redman patent, as previously described. Often, the increase in efficiency is as high as about to 70 A 15 gram melt was prepared and polished glass discs prepared therefrom as described in Part A of Example 50 1, except the molar or weight percentages of the raw materials were as follows:

Ingredients Molc Percent Weight Percent Host Glass Laser Article Host Glass Laser Article TeO, 80.0 79.5 80.3 79.5 ZnO 10.0 9.9 5.1 5.0 PbO 10.0 9.9 14.1 13.8 M11 0 0.7 1.6

The refractive index of the finished polished glass disc perc nt or more for the glass compositions of the preswas measured to be 2 21 ent mventton, including those in the preferred range 1 within the area formed by the heavy lines connecting points GHIJ of the ternary diagram. PART B What is claimed is: The polished glass disc from Part A was tested for flu l. A laser glass host composition comprising TeO orescence intensity and decay time as described inPart PhD and ZnO in which the proportions in molar amounts of TeO PbO and ZnO are defined by the area within the heavy lines connecting the points ABCDEF of the ternary diagram of the Figure of the drawings, the laser glass host composition being a host for an effective lasing amount of Nd O 2. A laser glass host composition as defined in claim 1 in which the proportions of TeO PhD and ZnO in molar amounts are defined by the heavy lines connecting the points GHlJ of the ternary diagram of the Figure of the drawings.

3. A laser glass composition comprising:

i. a glass host containing about 60-82 mole percent TeO- about 2-25 mole percent PbO, and about -35 mole percent ZnO; and

2. an effective lasing amount of Nd O 4. A laser glass composition comprising about 65-80 mole percent TeO about 5-10 mole percent PbO and about -25 mole percent ZnO, and about 0.0l-l.5 mole percent M1 0 5. A laser glass composition as defined in claim 3 in which the glass comprises about 65 mole percent TeO about 10 mole percent PbO and about 25 mole percent ZnO.

6. A laser glass composition as defined in claim 3 in which the host comprises about 80 molepercent TeO about 10 mole percent PhD and about 10 mole percent ZnO.

7. A laser glass composition as defined in claim 3, the host comprising about mole percent TeO about 5 mole percent PbO and about 20 mole percent ZnO.

8. The new use for a glass composition as a glass laser article in which the glass comprises TeO PbO and ZnO, the molar portion thereof being defined by the area within the heavy lines connecting the points ABC- DEF in the ternary diagram in the FIGURE of the drawings, and which glass composition is a host for an effective lasing amount of Nd O the new use comprisl i s .3 .122

l. forming the glass laser articles;

2. pumping the laser article to provide an energy inversion; and

3. lasing the pumped article. 

1. A LASER GLASS HOST COMPOSITION COMPRISING TEO2, PBO AND ZNO IN WHICH THE PROPORTIONS IN MOLAR AMOUNTS OF TEO2, PBO AND ZNO ARE DEFINED BY THE AREA WITHIN THE HEAVY LINES CONNECTING THE POINTS ABCDEF ON THE TERNARY DIAGRAM O THE FIGURE OF THE DRAWINGS, THE LASER GLASS HOST COMPOSITION BEING A HOST FOR AN EFFECTIVE LASING AMOUNT OF ND2O3.
 2. A laser glass host composition as defined in claim 1 in which the proportions of TeO2, PbO and ZnO in molar amounts are defined by the heavy lines connecting the points GHIJ of the ternary diagram of the Figure of the drawings.
 2. pumping the laser article to provide an energy inversion; and
 2. an effective lasing amount of Nd2O3.
 3. lasing the pumped article.
 3. A laser glass compositiOn comprising:
 4. A laser glass composition comprising about 65-80 mole percent TeO2, about 5-10 mole percent PbO and about 10-25 mole percent ZnO, and about 0.01-1.5 mole percent Nd2O3.
 5. A laser glass composition as defined in claim 3 in which the glass comprises about 65 mole percent TeO2, about 10 mole percent PbO and about 25 mole percent ZnO.
 6. A laser glass composition as defined in claim 3 in which the host comprises about 80 mole percent TeO2, about 10 mole percent PbO and about 10 mole percent ZnO.
 7. A laser glass composition as defined in claim 3, the host comprising about 75 mole percent TeO2, about 5 mole percent PbO and about 20 mole percent ZnO.
 8. The new use for a glass composition as a glass laser article in which the glass comprises TeO2, PbO and ZnO, the molar portion thereof being defined by the area within the heavy lines connecting the points ABCDEF in the ternary diagram in the FIGURE of the drawings, and which glass composition is a host for an effective lasing amount of Nd2O3, the new use comprising the steps of: 